From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.1 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 49AFFC64EB8 for ; Wed, 3 Oct 2018 12:51:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0FC8E20684 for ; Wed, 3 Oct 2018 12:51:52 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="uVGUM5AV" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0FC8E20684 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726862AbeJCTkG (ORCPT ); Wed, 3 Oct 2018 15:40:06 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:59258 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726619AbeJCTkG (ORCPT ); Wed, 3 Oct 2018 15:40:06 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=m3XbzxDk3IIN9P2b8GBaOJpU4DnrUVoV+L2U+yZiVGs=; b=uVGUM5AVOEzVXqeaEtTap/8qK C0pOJtDDAZ7DtLwmH4V94ZYRvbZ9RbuucE3TErSly92prb+vXfFpwZ7DKrS5zksg4f+qNt9oEUfvR f179bDYPTDL7YHsKl+zeNqgaRm5y/oSK8/i1CF2Gb7QLion1NThc74gkhPcai6PuQuskzYMf5z/Lm rhPRU1kJm0RU2ztjadW+dmCGbzbo/JsuLGsNAspdb2+kl4QSY1VyS/Mftgntcv4jsjb6WQyVCZsEu U6XCxNL4TSYKF45SI3pok84buhd3Yu5RMVSiUM9CH76yo1fAYlv43lLCWSXXpLH+WpagiC/9hV4UQ 9nq3BIBsQ==; Received: from hch by bombadil.infradead.org with local (Exim 4.90_1 #2 (Red Hat Linux)) id 1g7gd0-000494-Sw; Wed, 03 Oct 2018 12:51:46 +0000 Date: Wed, 3 Oct 2018 05:51:46 -0700 From: Christoph Hellwig To: Damien Le Moal Cc: Linus Walleij , Artem Bityutskiy , Paolo Valente , Jens Axboe , linux-block , linux-mmc , "linux-mtd@lists.infradead.org" , Pavel Machek , Ulf Hansson , Richard Weinberger , Adrian Hunter , Jan Kara , "aherrmann@suse.com" , "mgorman@suse.com" , Chunyan Zhang , "linux-kernel@vger.kernel.org" , "bfq-iosched@googlegroups.com" , "oleksandr@natalenko.name" , Mark Brown Subject: Re: [PATCH] block: BFQ default for single queue devices Message-ID: <20181003125146.GA9313@infradead.org> References: <20181002124329.21248-1-linus.walleij@linaro.org> <05fdbe23-ec01-895f-e67e-abff85c1ece2@kernel.dk> <1538550325.14984.108.camel@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.9.2 (2017-12-15) X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Oct 03, 2018 at 07:42:15AM +0000, Damien Le Moal wrote: > Of note also is that host-managed like sequential zone devices are also likely > to show up soon with the work being done in the NVMe standard on the new "Zoned > namespace" feature proposal. These devices will also require a scheduler like > mq-deadline guaranteeing per-zone in-order delivery of sequential write > requests. Looking only at the number of queues of the device is not enough to > choose the best (most reasonnable/appropriate) scheduler. We actually have a plan to avoid the need for a non-reordering scheduler there (including a Linux prototype for it). Lets see if it survives the committee.